Isolation, identification, characterization, and screening of rhizospheric bacteria for herbicidal activity

  • Charles Oluwaseun Adetunji
  • Julius Kola Oloke
  • Gandham Prasad
  • Oluwasesan Micheal Bello
  • Osarenkhoe Omorefosa Osemwegie
  • Mishra Pradeep
  • Ravinder Sing Jolly
Article

DOI: 10.1007/s13165-017-0184-8

Cite this article as:
Adetunji, C.O., Oloke, J.K., Prasad, G. et al. Org. Agr. (2017). doi:10.1007/s13165-017-0184-8

Abstract

The consistent application of agrochemical herbicides has been reported to impact negatively on human health, environment, and food safety, and facilitated the emergence of weed resistances. Rhizosphere bacteria (RB) of different crops were screened for antagonism against Amaranthus hybridus L. (pigweed) and Echinochloa crus-galli (L.) Beauv. (barnyard grass) using necrosis assay technique. A total of eight rhizosphere bacterial isolates (B1–B8) produced different degrees of leaf necrosis on target weeds with isolate B2 manifesting the most significant necrotic activity. The rhizospheric bacterium (B2) with the highest necrotic activity was identified using 16S rRNA sequencing technique and further investigated. Molecular, morphological, and biochemical characterizations confirmed B2 isolate to be Pseudomonas aeruginosa. On isolation with ethyl acetate, separation, defatting, purification, and flash chromatography, seven different fractions (fraction 1–fraction 7) were obtained out of which fraction 4 showed the highest necrotic activity in necrosis assay experiment. Preparative HPLC of fraction 4 resulted in a pure compound that completely inhibited seed germination and seedling development of pigweed and barnyard grass but remained non-antagonistic to other tested soil fungi used in this study. The result obtained from this present study consequently confirmed the antagonistic behavior of rhizosphere-inhabiting P. aeruginosa to the target weeds and qualified the suitability of bacterium as good alternative source of bioherbicide. Potential herbicidal formulation from P. aeruginosa will help reduce crop loss due to weed challenges while offering a partial solution to the use of agrochemicals and food security.

Keywords

16S rRNA gene DNA sequencing Deleterious rhizosphere bacteria Phylogenetic tree PHPLC and bioherbicide 

Funding information

Funder NameGrant NumberFunding Note
Council of Scientific and Industrial Research (CSIR), New Delhi, India and The World Academy of Science (TWAS), Italy
  • FR number: 3240267282

Copyright information

© Springer Science+Business Media Dordrecht 2017

Authors and Affiliations

  • Charles Oluwaseun Adetunji
    • 1
  • Julius Kola Oloke
    • 2
  • Gandham Prasad
    • 3
  • Oluwasesan Micheal Bello
    • 4
  • Osarenkhoe Omorefosa Osemwegie
    • 1
  • Mishra Pradeep
    • 5
  • Ravinder Sing Jolly
    • 5
  1. 1.Department of Biological Sciences, Applied Microbiology, Biotechnology and Nanotechnology LaboratoryLandmark UniversityOmu AranNigeria
  2. 2.Department of Pure and Applied BiologyLadoke Akintola University of TechnologyOgbomosoNigeria
  3. 3.Microbial Type Culture Collection and Gene Bank, CSIR-Institute of Microbial TechnologyChandigarhIndia
  4. 4.Department of Applied ChemistryFederal University Dutsin-MaDutsin-MaNigeria
  5. 5.Department of Bioorganic LaboratoryInstitute of Microbial TechnologyChandigarhIndia

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